Sinus lift implant

ABSTRACT

A dental implant is provided that has a proximal-most part, a lateral external surface, and a distal implant portion that extends from a distal implant end along up to 50% of a longitudinal length of the implant. The implant is shaped so as to define a lumen therethrough (a) having at least one distal opening through a distal external surface of the distal implant portion, (b) having a lateral opening through the lateral external surface, and (c) not open to a proximal external surface of the implant within 2 mm of the proximal-most part of the implant. Other embodiments are also described.

FIELD OF THE INVENTION

The present invention relates generally to dental implants and implantation methods, and specifically to minimally-invasive sinus lift implants and implantation methods.

BACKGROUND OF THE INVENTION

Osseointegrated dental implants are typically metallic or ceramic screws that are placed in the jawbone for supporting artificial teeth after the loss of natural teeth. Replacement of the maxillary teeth is often a challenging surgical procedure when the remaining maxillary bone has insufficient height to support the implant. One surgical technique for augmenting the maxillary bone includes injecting a regenerative material, such as autogenic, allogeneic, xenogeneic, or synthetic bone graft, into the vicinity of the maxillary bone. The regenerative material forms additional bone mass that integrates with the existing maxillary bone, providing the necessary alveolar height to support the implant.

Bone augmentation procedures are often surgically difficult to perform, and are associated with complications, including infection of the maxillary sinus. The top of the maxillary alveolar ridge forms the floor of the maxillary sinus, and is covered by a thin membrane known as the Schneiderian or subantral membrane. In one surgical procedure, known as a closed or internal sinus lift or elevation procedure, the surgeon drills a bore through the maxillary alveolar ridge from the oral cavity at the desired location of the implant. The bore penetrates the ridge to below the Schneiderian membrane. The surgeon injects the regenerative material through the bore to below the membrane, forming a cavity defined by the top of the ridge and the bottom of the membrane, which cavity occupies a portion of the space initially occupied by the maxillary sinus.

To prevent potentially serious complications, the surgeon must be careful not to perforate the Schneiderian membrane. This is often difficult, because of the delicacy of the membrane, and the restricted access afforded by the closed approach.

Sotirakis E, in an article entitled, “A different method for elevation of the floor of the maxillary sinus: Experimental study and reference to some cases,” Mediterranean Dental Implant Congress (Athens, Greece), Scientific Programme MDIC (2004), relevant portions of which are incorporated herein by reference, describes a surgical procedure for elevating the antral floor using hydraulic pressure applied with a medical syringe. The procedure was first tested experimentally on hen's eggs as a surrogate sinus, and subsequently on human cadaver preparations.

Chen L et al., in an article entitled, “An 8-year retrospective study: 1,100 patients receiving 1,557 implants using the minimally invasive hydraulic sinus condensing technique,” J Periodontol 76:482-491 (2005), relevant portions of which are incorporated herein by reference, describe an internal crestal approach for performing sinus lift and placing endosseous implants. Sinus burs and condensers of increasing width were used in conjunction with pliable atraumatic bone grafting mixture and hydraulic pressure from a surgical handpiece. The risk of membrane perforation was reduced using the surgeon's tactile skill administered in a two-stage process to first loosen and then graft bone particulate under the Schneiderian membrane. Threaded implants were placed during the same procedure, and secured via primary closure.

US Patent Application Publication 2006/0084034 to Hochman, relevant portions of which are incorporated herein by reference, describes techniques for providing implants in the upper jaw. A sleeve is inserted through the alveolar ridge to the maxillary sinus. The sleeve is used to raise the subantral membrane and form a cavity. A filler, such as a bone growth stimulant, is injected through the sleeve into the cavity. In the process, the sleeve also can cut and/or condense the bone around itself so that the bone can hold an implant. Optionally, the bone growth stimulant is also introduced into the bone surrounding the sleeve. During the injection, the pressure within the sleeve or the cavity is monitored to detect and prevent the rupture of the subantral membrane.

US Patent Application Publication 2006/0172255 to Hochman et al., relevant portions of which are incorporated herein by reference, describes a surgical tool used for preparing a surgical sinus-lift osteotomy. The tool has a defined thread geometry in series with an osteotome tip to cut, crack and push bone from the sinus floor upward into the sinus cavity in a tactual, gentle and controlled motion. The apical osteotome tip is driven into a pre-drilled pilot osteotomy after the cutting threads are engaged and rotated until the sinus floor is cracked free. Once the bony sinus floor is cracked free, a fluid passageway can be pressurized with a sterile fluid at a defined pressure to release and push the sinus membrane upward into the sinus cavity to create a desired apical cavity for grafting.

US Patent Application Publication 2007/0162024 to Siemonsmeier, relevant portions of which are incorporated herein by reference, describes an implant comprising at least one shaft area for anchoring in a bony structure, and at least one opening at the distal end of the shaft area in which the shaft area has a continuous bore extending from the opening to at least one outlet at the apical end, so that targeted introduction of material at least into the periapical area is possible with a stable anchoring in the bone structure even after implantation.

U.S. Pat. No. 7,364,430 to Kitamura et al., relevant portions of which are incorporated herein by reference, describes a dental implant system and method. The dental implant system typically includes a boring device for boring a hole in an alveolar bone and leaving a bridge portion separating the hole from the maxillary sinus cavity. The system may also include a scoring device for scoring the bridge portion, and a lifting device for breaking the bridge portion along the score, and lifting the freed bridge portion a first predetermined distance. The system may further include a membrane separation elevator for separating the sinus membrane from the sinus cavity wall. The system may also include a second lifting device configured to contact the freed bridge portion to further raise the freed bridge portion and sinus membrane together to a second predetermined penetration distance into the sinus cavity.

U.S. Pat. No. 5,711,315 to Jerusalmy, relevant portions of which are incorporated herein by reference, describes a method for subantral augmentation including the steps of lifting the Schneiderian membrane from the antral floor, and placing graft material between the Schneiderian membrane and the antral floor, without fracturing the lateral maxillary wall.

U.S. Pat. No. 5,261,818 to Shaw, relevant portions of which are incorporated herein by reference, describes a dental drill having the form of a substantially solid cylindrical body having a cutting portion and a gripping shank. The cylindrical body includes a boss between the cutting portion and said gripping shank. Upon the cutting portion, between the boss and a tip of the cutting portion, are provided at least four axi-symmetric flutes upon a lateral surface of the cutting portion. Each of the flutes are substantially co-axial with the longitudinal axis of the drill, defining a substantially linear profile before reaching the conical tip of the cutting portion, at which each of the flutes narrows. The flutes are separated by substantially co-axial channels having radial depths of about one-eighth of the diameter of the cylindrical body. Each of the channels flare to a larger polar dimension at said tip of the cutting portion. The body is provided with an axial irrigation channel having at least one liquid outlet within each of the channels and proximally to the tip of the cutting portion of the drill.

U.S. Pat. No. 5,575,650 to Niznick et al., relevant portions of which are incorporated herein by reference, describes a twist-bladed dental drill with an enhanced cutting tip for preparing surgical sites for endosseous implants. The drill includes a central, axially-extending internal passageway for carrying fluid through the shank of the drill to the outer surfaces of the drill.

The following references, relevant portions of which are incorporated herein by reference, may be of interest:

-   U.S. Pat. No. 7,396,232 to Fromovich et al. -   U.S. Pat. No. 7,297,102 to Smith et al. -   U.S. Pat. No. 5,685,716 to Linkow -   U.S. Pat. No. 5,795,160 to Hahn et al. -   U.S. Pat. No. 5,839,899 to Robinson -   U.S. Pat. No. 5,879,161 to Lazzara -   U.S. Pat. No. 5,967,777 to Klein et al. -   U.S. Pat. No. 6,068,479 to Kwan -   U.S. Pat. No. 5,829,977 to Rogers et al. -   U.S. Pat. No. 5,782,918 to Klardie et al. -   U.S. Pat. No. 5,759,036 to Hinds -   U.S. Pat. No. 4,431,416 to Niznick -   U.S. Pat. No. 5,575,650 to Niznick et al. -   US Patent Application Publication 2003/0232308 to Simmons, Jr. -   U.S. Pat. No. 5,456,601 to Sendax -   US Patent Application Publication 2003/0105469 to Karmon -   U.S. Provisional Application 60/619,542 to Hochman -   PCT Publication WO 07/114,553 to Ahn -   PCT Publication WO 07/080,595 to Levi et al. -   Muronoi M et al., “Simplified procedure for augmentation of the     sinus floor using a haemostatic nasal balloon,” British Journal Of     Oral & Maxillofacial Surgery 41(2):120-121 (2003) -   Vercellotti T, “Piezoelectric surgery in implantology: a case     report—a new piezoelectric ridge expansion technique,” Int J     Periodontics Restorative Dent 20(4):358-65 (2000) -   Vercellotti T et al., “The Piezoelectric Bony Window Osteotomy and     Sinus Membrane Elevation Introduction of a New Technique for     Simplification of the Sinus Augmentation Procedure,” Int J     Periodontics Restorative Dent 21(6):561-7 (2001) -   Flanagan D, “Important arterial supply of the mandible, control of     an arterial hemorrhage, and report of a hemorrhagic incident,” J     Oral Implantol 29(4):165-73 (2003)

SUMMARY OF THE INVENTION

Some embodiments of the present invention provide a self-tapping osseointegrated dental implant and minimally-invasive closed sinus lift techniques for augmenting the maxillary alveolar ridge while reducing the risk of perforating the Schneiderian membrane and of infection. The dental implant is shaped so as to define a lumen therethrough having a distal opening through a distal external surface of a distal portion of the implant. During an implantation procedure, a surgeon simultaneously forms a bore through the maxillary alveolar ridge and advances the implant into the bore by screwing the implant into the ridge. While the surgeon screws the implant, a fluid is provided under monitored pressure to the distal implant portion via the lumen. A drop in the pressure is detected as the distal implant end forms an opening through the top of the ridge to below the Schneiderian membrane, thereby bringing the distal opening into fluid communication with a surface of the membrane facing the ridge. Upon detection of the pressure drop, the surgeon ceases screwing the implant to avoid perforating the membrane. The surgeon gently lifts and separates the membrane from the top of the ridge by injecting a fluid under controlled pressure via the lumen, so as to form a cavity below the membrane between the ridge and the membrane. The surgeon injects a regenerative material, such as liquid or gel bone graft, via the lumen into the cavity. The surgeon further screws the implant into the regenerative material in the cavity. After bone grows into the regenerative material, a dental appliance, such as a crown, is coupled to the implant.

In some embodiments of the present invention, a proximal end of the lumen of the implant has a lateral opening through a lateral external surface of the implant, and is not open to a proximal external surface of the implant within 2 mm of the proximal-most part of the implant. The implant typically is permanently closed within 3 mm of the proximal-most part. During the implantation procedure, the additional screwing of the implant into the regenerative material advances the lateral external surface of the implant until the lateral opening is positioned entirely within the bore in the ridge and/or within the regenerative material in the cavity between the ridge and the membrane. Such positioning of both ends of the lumen within bone (current or future) substantially reduces the risk of infection, because the proximal end of the implant that is exposed to the oral cavity or gingiva is permanently closed.

In some embodiments of the present invention, a delivery tube is coupled to the lumen via the lateral opening. After injecting the regenerative material into the cavity from the delivery tube via the lumen, the surgeon decouples the delivery tube from the implant before further rotating the implant to bring the lateral opening entirely within the bore in the ridge and/or the cavity. For some applications, the implant system comprises a swivel joint having proximal and distal joint portions, which define proximal and distal joint ports, respectively. The joint is arranged so as to define a fluid path from the proximal joint port to the distal joint port via the proximal and distal joint portions. The proximal and distal joint portions are arranged to be rotatable with respect to one another such that the fluid path is preserved during rotation. The proximal end of the delivery tube is coupled to the distal joint port, and a supply tube, which is coupled to a source of fluid, is coupled to the proximal joint port, such that the delivery tube and the supply tube are in fluid communication with one another via the swivel joint.

In some embodiments of the present invention, the implant comprises a valve arranged in a fluid path defined by the lumen, or in a fluid path defined by the delivery tube. For some applications, the valve is configured to allow passage of material through the lumen in a direction from the lateral opening toward the distal implant end, and to prevent the passage in an opposite direction. Alternatively, the valve may be configured to be bidirectional.

In some embodiments of the present invention, an applicator is removably coupled to the proximal end of the implant during a portion of an implantation procedure. The applicator comprises a chamber that is in fluid communication with the lumen, and an elastic pressure-applying element that is configured to apply pressure to the chamber. While the surgeon screws the implant into the ridge, pressure is applied by fluid in the chamber to the distal implant portion via the lumen. A drop in the pressure is detected as the distal implant end forms an opening through the top of the ridge to below a Schneiderian membrane, thereby bringing the distal opening into fluid communication with a surface of the membrane facing the ridge. Upon detection of the pressure drop, the surgeon ceases to screw the implant.

For some applications, the pressure is applied by initially inflating a balloon that defines the chamber with the fluid to greater than atmospheric pressure. Alternatively or additionally, the pressure is applied by the surgeon squeezing the chamber in conjunction with screwing the implant. For other applications, the elastic pressure-applying element comprises a piston and a spring configured to apply pressure to the chamber. For some applications, the chamber contains a fluid, and the applicator comprises an indicator element that is arranged with the piston to indicate when the pressure applied to the chamber has caused ejection of at least a portion of the fluid from the chamber out of the distal implant portion via the lumen.

For some applications, the implant comprises a plug removably coupled to the implant so as to seal the distal lumen end. The plug comes loose during the implantation procedure by friction generated by the screwing of the implant, allowing the fluid to escape from the chamber as the distal implant end forms the opening from the top of the ridge to below the membrane.

There is therefore provided, in accordance with an embodiment of the present invention, apparatus including:

a dental implant having a proximal-most part, a lateral external surface, and a distal implant portion that extends from a distal implant end along up to 50% of a longitudinal length of the implant,

the implant being shaped so as to define a lumen therethrough (a) having at least one distal opening through a distal external surface of the distal implant portion, (b) having a lateral opening through the lateral external surface, and (c) not open to a proximal external surface of the implant within 2 mm of the proximal-most part of the implant.

For some applications, the lumen is not open to the proximal external surface of the implant within 3 mm of the proximal-most part of the implant.

Typically, the at least one distal opening is located on the distal external surface at one or more locations selected from the group consisting of: a center of the distal implant end, a location on the distal implant end other than the center, and a location on the distal implant portion other than on the distal implant end.

Typically, the dental implant is permanently closed within 3 mm of the proximal-most part of the implant.

For some applications, the longitudinal length is less than 20 mm, and the implant has a greatest diameter of less than 10 mm.

For some applications, the lateral opening is at least 1.5 mm from the distal implant end, such as at least 2 mm from the proximal implant end, or at least 3 mm from the proximal implant end.

For some applications, at least a portion of the lateral external surface is shaped so as to define a cutting surface. For some applications, the lateral opening is within the portion of the lateral external surface that defines the cutting surface.

For some applications, at least a portion of the lateral external surface is shaped so as to define a screw thread. For some applications, the lateral opening is within the portion of the lateral external surface that defines the screw thread.

For some applications, the implant includes a valve arranged in a fluid path defined by the lumen. Typically, the valve is configured to allow passage of material through the lumen in a direction from the lateral opening toward the distal implant end, and to prevent the passage in an opposite direction.

In an embodiment, the apparatus further includes a delivery tube having a proximal tube end and a distal tube end, which distal tube end is removably coupled to the implant such that the delivery tube is in fluid communication with the lumen via the lateral opening when the delivery tube is coupled to the implant. For some applications, the delivery tube includes a valve arranged in a fluid path defined by the delivery tube. For some applications, the apparatus further includes a swivel joint having distal and proximal joint portions defining distal and proximal joint ports, respectively, the swivel joint arranged so as to define a fluid path from the proximal joint port to the distal joint port via the proximal and distal joint portions, which are arranged to be rotatable with respect to one another such that the fluid path is preserved during rotation, and the proximal tube end is coupled to the distal joint port. For some applications, the apparatus further includes an applicator, which is removably coupled to a proximal implant end of the implant, and the swivel joint defines a bore therethrough, in which at least a portion of the applicator is positioned.

There is further provided, in accordance with an embodiment of the present invention, a method including:

providing a dental implant having a proximal-most part, a lateral external surface, and a distal implant portion that extends from a distal implant end along up to 50% of a longitudinal length of the implant, the implant shaped so as to define a lumen therethrough (a) having at least one distal opening through a distal external surface of the distal implant portion, (b) having a lateral opening through the lateral external surface, and (c) not open to a proximal external surface of the implant within 2 mm of the proximal-most part of the implant;

forming a bore through a maxillary alveolar ridge;

inserting the implant into the bore at least until the distal opening comes into fluid communication with a surface of a Schneiderian membrane facing the ridge; and

raising the membrane to form a cavity between the ridge and the membrane.

Typically, forming the bore includes forming at least a portion of the bore by inserting the implant into the ridge and rotating the implant. For some applications, forming the bore includes forming a preparatory portion of the bore using a dental drill, and subsequently forming the at least a portion of the bore by inserting the implant into the ridge and rotating the implant.

In an embodiment, the method further includes: after raising the membrane, injecting a regenerative material into the cavity via the lumen; and, after injecting the material, further rotating the implant until the lateral opening is positioned entirely within at least one location selected from the group consisting of the bore in the ridge, and the cavity between the ridge and the membrane. For some applications, injecting includes injecting the regenerative material via the lumen from a delivery tube removably coupled to the implant such that the delivery tube is in fluid communication with the lumen via the lateral opening when the delivery tube is coupled to the implant, and the method further includes, after injecting the material and before the lateral opening is positioned entirely within the at least one location, decoupling the delivery tube from the implant. For some applications, raising the membrane includes injecting a fluid through the bore, and measuring a volume of the injected fluid, and injecting the regenerative material includes determining an amount of the regenerative material to inject into the cavity responsively to the measured volume of the fluid.

There is still further provided, in accordance with an embodiment of the present invention, a method including:

providing a dental implant having a proximal-most part, a lateral external surface, and a distal implant portion that extends from a distal implant end along up to 50% of a longitudinal length of the implant, the implant shaped so as to define a lumen therethrough having at least one distal opening through a distal external surface of the distal implant portion, having a lateral opening through the lateral external surface, and not open to a proximal external surface of the implant within 2 mm of the proximal-most part of the implant;

forming a bore through a maxillary alveolar ridge;

inserting the implant into the bore at least until the distal opening comes into fluid communication with a surface of a nasal floor membrane facing the ridge; and

raising the membrane to form a cavity between the ridge and the membrane.

There is additionally provided, in accordance with an embodiment of the present invention, apparatus including:

a dental implant having a proximal implant end, a lateral external surface, and a distal implant portion that extends from a distal implant end along up to 50% of a longitudinal length of the implant, wherein the lateral external surface is indented so as to define a channel along the lateral external surface between (a) a first location on the distal implant portion on the lateral external surface and (b) a second location on the lateral external surface between the first location and the proximal implant end, not inclusive; and

a delivery tube, a distal portion of which is positioned within the channel.

For some applications, the second location is at least 2 mm from the proximal implant end.

For some applications, at least a portion of the lateral external surface is shaped so as to define a screw thread including a raised helical rib going around the implant, and the channel crosses the rib at a plurality of sites on the lateral external surface.

For some applications, the apparatus further includes a swivel joint having distal and proximal joint portions defining distal and proximal joint ports, respectively, the swivel joint arranged so as to define a fluid path from the proximal joint port to the distal joint port via the proximal and distal joint portions, which are arranged to be rotatable with respect to one another such that the fluid path is preserved during rotation, and a proximal end of the delivery tube is coupled to the distal joint port.

For some applications, the longitudinal length is less than 20 mm, and the implant has a greatest diameter of less than 10 mm.

There is yet additionally provided, in accordance with an embodiment of the present invention, a method including:

providing (i) a dental implant having a proximal implant end, a lateral external surface, and a distal implant portion that extends from a distal implant end along up to 50% of a longitudinal length of the implant, wherein the lateral external surface is indented so as to define a channel along the lateral external surface between (a) a first location of the distal implant portion on the lateral external surface and (b) a second location on the lateral external surface between the first location and the proximal implant end, not inclusive, and (ii) a delivery tube, a distal portion of which is positioned within the channel;

forming a bore through a maxillary alveolar ridge;

inserting the implant into the bore at least until the first location comes into fluid communication with a surface of a Schneiderian membrane facing the ridge; and

raising the membrane to form a cavity between the ridge and the membrane.

Typically, forming the bore includes forming at least a portion of the bore by inserting the implant into the ridge and rotating the implant. For some applications, forming the bore includes forming a preparatory portion of the bore using a dental drill, and subsequently forming the at least a portion of the bore by inserting the implant into the ridge and rotating the implant.

In an embodiment, the method further includes: after raising the membrane, injecting a regenerative material into the cavity via a delivery tube, a distal portion of which is positioned within the channel; and, after injecting the material, further rotating the implant until the second location is positioned entirely within at least one location selected from the group consisting of: the bore in the ridge, and the cavity between the ridge and the membrane. For some applications, the method further includes, after injecting the material and before the second location is positioned entirely within the at least one location, removing the delivery tube from the channel. For some applications, raising the membrane includes injecting a fluid through the bore, and measuring a volume of the injected fluid, and injecting the regenerative material includes determining an amount of the regenerative material to inject into the cavity responsively to the measured volume of the fluid.

There is also provided, in accordance with an embodiment of the present invention, a method including:

providing a dental implant having a lateral external surface and a distal implant portion that extends from a distal implant end along up to 50% of a longitudinal length of the implant, the implant shaped so as to define a lumen therethrough having at least one distal opening through a distal external surface of the distal implant portion;

forming a bore through an alveolar ridge by inserting the implant into the ridge and rotating the implant;

while forming the bore, providing a fluid under pressure to the distal implant portion via the lumen, and monitoring the pressure of the fluid; and

detecting a drop in the pressure as the distal opening comes into fluid communication with the area beyond the ridge.

For some applications, the alveolar ridge is a maxillary alveolar ridge, forming the bore includes forming the bore through the maxillary alveolar ridge, and detecting includes detecting the drop in the pressure as the distal opening comes into the fluid communication with a surface of a Schneiderian membrane facing the ridge.

For some applications, the alveolar ridge is a mandibular alveolar ridge, forming the bore includes forming the bore through the mandibular alveolar ridge, and detecting includes detecting the drop in the pressure as the distal opening comes into fluid communication with an area beyond the mandibular alveolar ridge.

For some applications, the alveolar ridge is a maxillary alveolar ridge, forming the bore includes forming the bore through the maxillary alveolar ridge, and detecting includes detecting the drop in the pressure as the distal opening comes into the fluid communication with a surface of a nasal floor membrane facing the ridge.

Typically, rotating the implant includes ceasing to rotate the implant responsively to detecting the pressure drop.

For some applications, providing the implant includes providing the implant shaped such that the lumen is open to the lateral external surface and not open to a proximal external surface of the implant within 2 mm of a proximal-most part of the implant.

There is further provided, in accordance with an embodiment of the present invention, a method including:

providing a dental drill bit having (a) a distal bit portion that extends from a distal bit end along up to 6 mm of a longitudinal length of the bit, and (b) a lateral external surface that is shaped so as to define a cutting surface at least in a vicinity of the distal bit end, the bit shaped so as to define a lumen therethrough having at least one distal opening through a distal external surface of the distal bit portion;

forming a bore through a bone by inserting the bit into the bone and rotating the bit using a drill;

while forming the bore, providing a fluid under pressure to the distal bit portion via the lumen, and monitoring the pressure of the fluid; and

detecting a drop in the pressure as the distal opening comes into fluid communication with an area beyond the bone.

For some applications, the distal bit portion extends from the distal bit end along up to 4 mm of the longitudinal length of the bit, such as along up to 2 mm of the longitudinal length of the bit.

For some applications, the bone is a maxillary alveolar ridge, forming the bore includes forming the bore through the maxillary alveolar ridge, and detecting includes detecting the drop in the pressure as the distal opening comes into the fluid communication with a surface of a Schneiderian membrane facing the ridge.

For some applications, the bone is a mandibular alveolar ridge, forming the bore includes forming the bore through the mandibular alveolar ridge, and detecting includes detecting the drop in the pressure as the distal opening comes into the fluid communication with the area beyond the mandibular alveolar ridge.

For some applications, the bone is a maxillary alveolar ridge, forming the bore includes forming the bore through the maxillary alveolar ridge, and detecting includes detecting the drop in the pressure as the distal opening comes into the fluid communication with a surface of a nasal floor membrane facing the ridge.

For some applications, the bone is an alveolar ridge, forming the bore includes forming a first bore with an inclined entry at a first location on the ridge, and the method further includes: injecting a regenerative material through the first bore; forming a second bore at a second location on the ridge; and inserting a dental implant into the second bore.

For some applications, the bone is a palate, wherein forming the bore includes forming a first bore at a first location on the palate, and the method further includes: injecting a regenerative material through the first bore; forming a second bore at a second location on a maxillary alveolar ridge; and inserting a dental implant into the second bore.

Typically, rotating the bit includes ceasing to rotate the bit responsively to detecting the pressure drop.

There is still further provided, apparatus including:

a dental implant having a distal implant portion that extends from a distal implant end along up to 50% of a longitudinal length of the implant, the implant shaped so as to define a lumen through the implant, which lumen has at least one distal opening through a distal external surface of the distal implant portion; and

a swivel joint having distal and proximal joint portions defining distal and proximal joint ports, respectively, the swivel joint arranged so as to define a fluid path from the proximal joint port to the distal joint port via the proximal and distal joint portions, which are arranged to be rotatable with respect to one another such that the fluid path is preserved during rotation,

wherein the fluid path through the swivel joint is in fluid communication with the lumen via the distal joint port.

For some applications, the apparatus further includes an applicator, which is removably coupled to a proximal implant end of the dental implant, and the swivel joint defines a bore therethrough, in which at least a portion of the applicator is positioned.

For some applications, the implant is shaped such that the lumen has a lateral opening through a lateral external surface of the dental implant, and the apparatus further includes a delivery tube having (a) a proximal tube end that is coupled to the distal joint port, and (b) a distal tube end that is removably coupled to the implant such that the delivery tube is in fluid communication with the lumen via the lateral opening when the delivery tube is coupled to the implant.

For some applications, the implant is shaped such that the lumen is open to a proximal end of the dental implant through a proximal opening of the implant.

For some applications, the longitudinal length is less than 20 mm, and the implant has a greatest diameter of less than 10 mm.

There is additionally provided, in accordance with an embodiment of the present invention, apparatus including:

a dental implant having a distal implant portion that extends from a distal implant end along up to 50% of a longitudinal length of the implant,

the implant being shaped so as to define a lumen therethrough having a proximal opening and a distal opening through a distal external surface of the distal implant portion, and

the implant including a valve arranged in a fluid path defined by the lumen.

For some applications, the valve is configured to allow passage of material through the lumen in a direction from the proximal opening toward the distal opening, and to prevent the passage in an opposite direction.

For some applications, the longitudinal length is less than 20 mm, and the implant has a greatest diameter of less than 10 mm.

For some applications, the implant is shaped such that the proximal opening is through a lateral external surface of the implant, and the apparatus further includes a delivery tube removably coupled to the implant such that the delivery tube is in fluid communication with the lumen via the proximal opening when the delivery tube is coupled to the implant. For some applications, the valve is configured to allow bidirectional flow through the lumen when the valve is in an open position, and to block the flow when the valve is in a closed position. For some applications, the valve is configured to assume the open position by being pushed open by the delivery tube when the delivery tube is coupled to the implant, and to assume the closed position when the delivery tube is not coupled to the implant. For some applications, the valve includes an opening/closing control element that is accessible from outside of the implant.

There is still additionally provided, in accordance with an embodiment of the present invention, a method including:

providing a dental implant having a distal implant portion that extends from a distal implant end along up to 50% of a longitudinal length of the implant, the implant shaped so as to define a lumen therethrough having a proximal opening and a distal opening through a distal external surface of the distal implant portion, and the implant including a valve arranged in a fluid path defined by the lumen; and

forming a bore through a portion of a maxillary alveolar ridge by inserting the implant into the ridge and rotating the implant at least until the distal opening comes into fluid communication with a surface of a Schneiderian membrane facing the ridge.

For some applications, the valve is configured to allow passage of material through the lumen in a direction from the proximal opening toward the distal opening, and to prevent the passage in an opposite direction.

For some applications, the implant is shaped such that the proximal opening is through a lateral external surface of the implant, and the method further includes:

after the distal opening comes into the fluid communication with the surface of the membrane, injecting a regenerative material into the cavity via the lumen from a delivery tube removably coupled to the implant such that the delivery tube is in fluid communication with the lumen via the proximal opening when the delivery tube is coupled to the implant;

after injecting the material, decoupling the delivery tube from the implant; and

after injecting the material, further rotating the implant to further advance the distal implant end.

There is also provided, in accordance with an embodiment of the present invention, apparatus including:

a dental implant having a proximal implant end, a distal implant end, and a lateral external surface; and

a removable sheath covering at least a portion of the lateral external surface, such that at least a portion of the distal implant end is exposed.

For some applications, the implant is shaped so as to define a lumen therethrough having at least one distal opening through a distal external surface of a distal implant portion that extends from the distal implant end along up to 50% of a longitudinal of the implant.

For some applications, the implant has a longitudinal length of less than 20 mm and a greatest diameter of less than 10 mm.

There is further provided, in accordance with an embodiment of the present invention, a method including:

providing (a) a dental implant having a proximal implant end, a distal implant end, and a lateral external surface, and (b) a removable sheath covering at least a portion of the lateral external surface, such that at least a portion of the distal implant end is exposed;

inserting the implant into an alveolar ridge; and

inhibiting infection, by removing the sheath from the implant in conjunction with the inserting.

There is still further provided, in accordance with an embodiment of the present invention, apparatus including:

a dental implant having a distal implant portion that extends from a distal implant end along up to 50% of a longitudinal length of the implant, the implant shaped so as to define a lumen therethrough having at least one distal opening through a distal external surface of the distal implant portion; and

an applicator, which is removably coupled to the proximal implant end, and which includes a chamber that is in fluid communication with the lumen, and an elastic pressure-applying element that is configured to apply pressure to the chamber.

For some applications, the applicator is sized to be positioned entirely within an oral cavity.

For some applications, the elastic pressure-applying element includes a balloon shaped so as to define the chamber.

For some applications, the apparatus further includes a fluid with which the chamber is filled at a pressure greater than atmospheric pressure.

For some applications, the lumen has a proximal opening through a proximal external surface of a proximal implant end of the implant.

For some applications, the longitudinal length is less than 20 mm, and the implant has a greatest diameter of less than 10 mm.

For some applications, the apparatus further includes a plug removably coupled to the implant so as to seal the distal opening. For some applications, the plug is removable from the implant by friction generated during screwing of the dental implant. For some applications, the plug includes a biodegradable material. For some applications, the plug includes a regenerative material.

In an embodiment, the lumen has a proximal opening through a lateral external surface of the implant, and the lumen is not open to a proximal external surface of the implant within 2 mm of a proximal-most part of the implant. For some applications, the apparatus further includes a delivery tube having (a) a proximal tube end that is in fluid communication with the chamber, and (b) a distal tube end that is removably coupled to the implant such that the chamber is in fluid communication with the lumen via the delivery tube via the proximal opening when the delivery tube is coupled to the implant.

In an embodiment, the elastic pressure applying element includes a piston and a spring configured to apply pressure to the chamber. For some applications, the chamber contains a fluid, and the applicator includes an indicator element that is arranged with the piston to indicate when the pressure applied to the chamber has caused ejection of at least a portion of the fluid from the chamber out of the distal opening via the lumen.

There is additionally provided, in accordance with an embodiment of the present invention, a method including:

providing (a) a dental implant having a distal implant portion that extends from a distal implant end along up to 50% of longitudinal length of the implant, the implant shaped so as to define a lumen therethrough having at least one distal opening through a distal external surface of the distal implant portion, (b) an applicator, which is removably coupled to the proximal implant end, and which includes a chamber that is in fluid communication with the lumen, and (c) a fluid contained within the chamber;

forming a bore through a portion of a maxillary alveolar ridge by inserting the applicator into an oral cavity of the subject, inserting the implant into the ridge, and rotating the implant;

while forming the bore, applying pressure by the fluid to the distal implant portion via the lumen, and monitoring the pressure of the fluid; and

detecting a drop in the pressure as the distal opening comes into fluid communication with a surface of a Schneiderian membrane facing the ridge.

For some applications, inserting the applicator into the oral cavity includes inserting the entire applicator, including the entire chamber, into the oral cavity.

For some applications, applying the pressure includes squeezing the chamber in conjunction with rotating the implant.

Typically, the method further includes ceasing to rotate the implant responsively to detecting the pressure drop.

For some applications, applying the pressure includes providing a balloon shaped so as to define the chamber. For some applications, applying the pressure includes initially inflating the balloon with the fluid to greater than atmospheric pressure.

There is still additionally provided, in accordance with an embodiment of the present invention, a method including:

providing a plurality of dental implants having respective lateral external surfaces and respective distal implant portions that extend from respective distal implant ends along up to 50% of respective longitudinal lengths of the implants, the implants shaped so as to define respective lumens therethrough having respective distal openings through respective distal external surfaces of the distal implant portions;

forming a respective plurality of bores through respective portions of a maxillary alveolar ridge by, for each of the bores, inserting one of the implants into the ridge and rotating the implant; and

after forming the bores, lifting a Schneiderian membrane by injecting a material under the Schneiderian membrane through each of the implants in turn.

For some applications, forming each of the bores using a respective one of the implants includes:

while forming the bore, providing a fluid under pressure to the distal implant portion via the lumen, and monitoring the pressure of the fluid;

detecting a drop in the pressure as the distal opening comes into fluid communication with a surface of the Schneiderian membrane facing the ridge; and

ceasing to rotate the implant responsively to detecting the pressure drop.

There is also provided, in accordance with an embodiment of the present invention, apparatus including a dental sleeve, which is configured to be inserted into a bore formed through a portion of a maxillary alveolar ridge, and which includes:

a tubular portion having proximal and distal ends, and shaped so as to define a lumen therethrough; and

a biodegradable valve coupled to the distal end of the tubular portion, and configured to allow flow through the lumen in a direction from the proximal end to the distal end, and to prevent flow in an opposite direction.

For some applications, the valve includes a duckbill check valve.

For some applications, the tubular portion is biodegradable.

For some applications, the tubular portion and valve are configured to be readily separated from one another.

For some applications, the dental sleeve has a longitudinal length of less than 20 mm and a greatest diameter of less than 10 mm.

There is further provided, in accordance with an embodiment of the present invention, a method including:

forming a bore through a maxillary alveolar ridge;

lifting a Schneiderian membrane via the bore to form a cavity between the ridge and the membrane;

after lifting the membrane, inserting into the bore a dental sleeve including (a) a tubular portion having proximal and distal ends, and shaped so as to define a lumen therethrough, and (b) a biodegradable valve coupled to the distal end of the tubular portion, and configured to allow flow through the lumen in a direction from the proximal end to the distal end, and to prevent the flow in an opposite direction;

after inserting the sleeve, injecting a regenerative material through the lumen and valve into the cavity; and

after inserting the sleeve, leaving the valve in place to biodegrade.

In an embodiment, the method further includes mounting a dental implant in the bore by rotating the implant at least until a distal portion thereof breaks through the valve into the cavity between the ridge and the membrane.

For some applications, the tubular portion is biodegradable, and leaving the valve in place further includes leaving the tubular portion in place.

For some applications, leaving the valve in place includes separating the tubular portion from the valve, withdrawing the tubular portion from the bore, and leaving the valve in place to biodegrade.

For some applications, the valve includes a duckbill check valve.

There is still further provided, in accordance with an embodiment of the present invention, apparatus for use with a subject, the apparatus including:

a dental drilling element having a distal end;

a light source, which is configured to emit light into a body cavity of the subject;

a light sensor, which is configured to sense a level of illumination at the distal end of the drilling element; and

an output unit, which is configured to generate an output responsively to the level of the illumination.

For some applications, the light source is configured to be placed at least partially within the body cavity. Alternatively, the light source is configured to be placed outside of the body cavity.

For some applications, the light source is configured to emit the light from the distal end of the drilling element.

There is additionally provided, in accordance with an embodiment of the present invention, apparatus for use with a subject, the apparatus including:

a dental drilling element having a distal end;

a light source, which is configured to emit light from the distal end of the drilling element;

a light sensor, which is configured to sense a level of illumination within a body cavity of the subject; and

an output unit, which is configured to generate an output responsively to the level of the illumination.

For some applications, the light sensor is configured to be placed at least partially within the body cavity. Alternatively, the light sensor is configured to be placed outside of the body cavity.

There is yet additionally provided, in accordance with an embodiment of the present invention, a method including:

forming a bore in a maxillary alveolar ridge of a subject by inserting a dental drilling element into the ridge and rotating the drilling element;

emitting light into a body cavity of the subject;

sensing a level of illumination at a distal end of the drilling element; and

generating an output responsively to the level of the illumination.

For some applications, the method further includes ceasing to rotate the drilling element responsively to ascertaining that the level of illumination passes a threshold level.

For some applications, emitting the light includes placing a light source at least partially within the body cavity, and emitting the light from the light source. Alternatively, emitting the light includes emitting the light at a location outside of the body cavity in a vicinity thereof.

For some applications, emitting the light includes emitting the light from the distal end of the drilling element.

There is also provided, in accordance with an embodiment of the present invention, a method including:

forming a bore in a maxillary alveolar ridge of a subject by inserting a dental drilling element into the ridge and rotating the drilling element;

emitting light from a distal end of the drilling element;

sensing a level of illumination within a body cavity of the subject; and

generating an output responsively to the level of the illumination.

For some applications, the method further includes ceasing to rotate the drilling element responsively to ascertaining that the level of illumination passes a threshold level.

For some applications, sensing includes sensing the level of illumination by placing a light sensor at least partially within the body cavity and sensing using the light sensor. Alternatively, sensing includes sensing the level of illumination within the body cavity from outside the body cavity in a vicinity thereof.

There is further provided, in accordance with an embodiment of the present invention, a regenerative composition including:

a physiological solution; and

solid bone graft particles mixed with the physiological solution at a volume concentration of less than 50%.

For some applications, the volume concentration of the particles is less than 25%.

For some applications, the particles include freeze-dried bone allograft (FDBA).

For some applications, the physiological solution is selected from the group consisting of: saline solution, blood, and diluted blood.

There is still further provided, in accordance with an embodiment of the present invention a method including:

forming at least one bore through a bone from a first side of the bone to a second side of the bone;

raising a membrane on the second side of the bone to form a cavity between the second side of the bone and the membrane; and

injecting into the cavity via the bore a composition including saline solution and solid bone graft particles mixed with the saline solution at a volume concentration of less than 50%.

For some applications, forming the bore includes forming the bore through a maxillary alveolar ridge, and raising the membrane includes raising a Schneiderian membrane.

For some applications, forming the at least one bore includes forming first and second bores through the bone, and injecting includes injecting the composition into the cavity via the first bore, such that at least a portion of the saline solution drains from the cavity via the second bore, leaving at least a portion of the solid bone graft particles in the cavity.

For some applications, the volume concentration of the particles is less than 25%.

For some applications, the particle include freeze-dried bone allograft (FDBA).

For some applications, the physiological solution is selected from the group consisting of: saline solution, blood, and diluted blood.

The present invention will be more fully understood from the following detailed description of embodiments thereof, taken together with the drawings, in which:

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic illustration of a dental implant system, in accordance with an embodiment of the present invention;

FIGS. 2A-C are schematic illustrations of alternative configurations of a dental implant of the dental implant system of FIG. 1, in accordance with respective embodiments of the present invention;

FIG. 2D is a schematic illustration of yet another configuration of the dental implant of FIG. 1, and FIG. 2E is a cross-sectional view taken along line IIC-IIC of FIG. 2D, in accordance with an embodiment of the present invention;

FIG. 2F is a schematic illustration of a removable coupling element coupled to the dental implant of FIG. 1, in accordance with an embodiment of the present invention;

FIGS. 3A-F are schematic illustrations of several steps of a minimally-invasive closed sinus lift surgical procedure for implanting the dental implant of FIG. 1, in accordance with an embodiment of the present invention;

FIGS. 4A and 4B are schematic illustrations of respective configurations of the dental implant of FIG. 1 in which the implant comprises a valve, in accordance with respective embodiments of the present invention;

FIG. 5 is a schematic illustration of a dental drill, in accordance with an embodiment of the present invention;

FIGS. 6A-C are schematic illustrations of configurations of another dental implant system, in accordance with respective embodiments of the present invention;

FIG. 7 is a schematic illustration of a removable sheath applied to a dental implant, in accordance with an embodiment of the present invention;

FIGS. 8A and 8B are schematic illustrations of a biodegradable dental sleeve in closed and open positions, respectively, in accordance with an embodiment of the present invention; and

FIG. 9 is a schematic illustration a controlled bone penetration system, in accordance with an embodiment of the present invention.

DETAILED DESCRIPTION OF EMBODIMENTS

FIG. 1 is a schematic illustration of a dental implant system 20, in accordance with an embodiment of the present invention. System 20 comprises a dental implant 30, which is typically shaped so as to define a lumen 40 therethrough that is open through a distal opening 41 to a distal portion 48 of the implant that extends from a distal implant end 38 of the implant along up to 50% of a longitudinal length of the implant, such as up to 30% of the length, up to 15% of the length, or up to 5% of the length. For some applications, distal portion 48 has a longitudinal length of up to 6 mm, such as up to 4 mm, or up to 2 mm. As used herein, including in the claims, the “distal” end of the implant is the end that is inserted first into a bone, such as an alveolar ridge, and is sometimes referred to in the art as the apical end, and the “proximal” end of the implant is the end of the implant opposite the distal end, e.g., that faces the oral cavity, and is sometimes referred to in the art as the coronal end. Similarly, “distal” means situated toward the distal end of the implant, and “proximal” means situated toward the proximal end of the implant.

Distal opening 41 may be located at distal implant end 38, such as centered on the distal implant end, e.g., at a distal tip of distal implant end 38, or not centered on the distal implant end (and thus located at a location other than the distal tip), such as described hereinbelow with reference to FIG. 2A. Alternatively, distal opening(s) 41 may be located at one or more locations along distal implant portion 48, including at locations on lateral surface 42. For some applications, the lumen is open to the distal end via a plurality of openings 41, which for some applications results in a more even distribution of regenerative material in the cavity between the ridge and the Schneiderian membrane, as described hereinbelow, and/or permits passage of the regenerative material even if some of the openings should become blocked with bone particles. Dental implant 30 is typically generally cylindrical, tapered, or conic in shape, other than the lumen, and typically comprises a metal such as titanium, or a ceramic, such as a zirconia (zirconium dioxide) ceramic. The implant may have a greatest diameter of between about 2 and about 7 mm, and may be provided in a variety of longitudinal lengths, e.g., between about 7 and about 18 mm, e.g., between about 12 and about 16 mm, such as about 15 mm. For some applications, the implant has a longitudinal length of less than 20 mm and a greatest diameter of less than 10 mm.

In an embodiment of the present invention, dental implant 30 comprises a self-tapping osseointegrated dental implant. In this embodiment, at least a portion of a lateral external surface 42 of implant 30 is typically shaped so as to define a cutting surface, e.g., a screw thread 36, or other connecting element. For example, the portion may be in a vicinity of a distal end 38 of the implant, or may include all or nearly all of the lateral surface.

In an embodiment of the present invention, system 20 comprises an applicator 32 that is removably coupled to a proximal end 34 of implant 30. For some applications, applicator 32 is shaped so as to define a distal male coupling element, e.g., a hexagonal head, that is inserted into a correspondingly shaped proximal female coupling element, e.g., a hexagonal socket, defined by dental implant 30. Friction between the head and socket removably couples the implant to the applicator. Alternatively, another coupling element removably couples the implant to the applicator. A proximal end of applicator 32 is typically shaped so as to define a coupling element 43, such as a male coupling element (as shown in FIG. 1), e.g., a hexagonal head, or a female coupling element (configuration not shown), e.g., a hexagonal socket. Typically, implant 30 comprises a two-stage implant. The surgeon couples an abutment to the proximal end of the implant after osseointegration of the implant, as is known in the art, such as described hereinbelow with reference to FIG. 3F. Alternatively, implant 30 comprises a single-stage transgingival implant, which is shaped so as to define an integrated abutment, as is known in the art.

In an embodiment of the present invention, as shown in FIG. 1, a proximal end of lumen 40 has a lateral opening 44 through lateral external surface 42 of the implant, and the lumen is not open to a proximal external surface of the implant within 2 mm of a proximal-most part of implant 30. For some applications, the lumen is not open to the proximal external surface within 3 mm of the proximal-most part of the implant. Implant 30 is typically permanently closed within 3 mm of the proximal-most part of the implant, in this embodiment. Alternatively, the proximal end of lumen 40 is open to proximal implant end 34, such as described hereinbelow with reference to FIGS. 6A and 6C. Typically, the lateral opening is at least 1.5 mm from distal implant end 38, such as at least 2 mm (e.g., 8 mm from the distal implant end). Typically, the lateral opening is at least 2 mm from the proximal implant end, such as at least 3 mm or at least 4 mm.

System 20 further comprises a delivery tube 50, a distal end of which is coupled to lumen 40 via lateral opening 44. For example, the delivery tube may be coupled to the lumen using a miniature luer connector, by friction, or using a removable coupling element, as described hereinbelow with reference to FIG. 2F. Alternatively, the tube may screw into the lumen, so as to be rotationally secured to the implant throughout the implantation procedure. Typically, a proximal end of delivery tube 50 is coupled to applicator 32 during at least a portion of an implantation procedure. Delivery tube 50 is in fluid communication with a supply tube 52, which in turn is in fluid communication with a source of fluid 54. Alternatively, delivery tube 50 is coupled directly to fluid source 54, and supply tube 52 is not provided. Fluid source 54 may comprise a syringe or powered drug delivery device.

In an embodiment of the present invention, implant system 20 comprises a swivel joint 64 having proximal and distal joint portions 60 and 62, which define proximal and distal joint ports, respectively. Joint 64 is arranged so as to define a fluid path from the proximal joint port to the distal joint port via proximal and distal joint portions 60 and 62. Proximal and distal joint portions 60 and 62 are arranged to be rotatable with respect to one another such that the fluid path is preserved during rotation. The proximal end of delivery tube 50 is coupled to the distal joint port, and supply tube 52 is coupled to the proximal joint port, such that delivery tube 50 and supply tube 52 are in fluid communication with one another via swivel joint 64.

For some applications, as shown in FIG. 1, swivel joint 64 defines a bore therethrough, in which at least a portion of applicator 32 is positioned. The proximal and distal portions of the joint are independently rotatable around the portion of the applicator in the bore. Rotation of coupling element 43 at the proximal end of the applicator causes corresponding rotation of the distal end of the applicator and implant 30. Such rotation of the implant causes corresponding rotation of lateral opening 44 and delivery tube 50, which rotates distal joint portion 62 of swivel joint 64. However, supply tube 52 tends to prevent rotation of proximal joint portion 60 of the swivel joint, causing the proximal and distal joint portions to rotate with respect to one another. Alternatively, the applicator may be rotated by grasping it near or at its distal end. Optionally, distal joint portion 62 of swivel joint 64 is fixed to the body of applicator 32.

For some applications, lumen 40 is open to proximal implant end 34 rather than lateral surface 42. For these applications, the distal joint port may open to the bore of the swivel joint, and be in fluid communication with lumen 40 via a central lumen of the applicator (configuration not shown).

For some applications in which distal joint portion 62 of swivel joint 64 is fixed to the body of applicator 32, the implant is rotated by rotating the distal joint portion. For example, an external surface of the distal joint portion may be shaped so as to define a hexagon that is larger than proximal joint portion 60, and the distal joint portion may be rotated using a hexagonal ratchet wrench.

In an embodiment of the present invention, system 20 does not comprise applicator 32. System 20 comprises swivel joint 64, which, for some applications, is coupled to implant 30 only by delivery tube 50. To rotate the implant, a head of a wrench or other tool (e.g., a straight hexagonal screwdriver having a length of about 3 to 4 cm, optionally with a knurled handle) is temporarily inserted through the bore of the swivel joint, and coupled to the coupling element of the implant, which may be a hexagonal socket, for example. Alternatively, the swivel joint is removably coupled to the implant, and removed when delivery tube 50 is decoupled from the implant, as described hereinbelow with reference to FIG. 3E. For some applications in which the swivel joint is removably coupled to the implant, distal joint portion 62 is shaped so as to define a coupling element, such as a hexagonal coupling element, and the implant is rotated by rotating the coupling element using a wrench or hexagonal screwdriver.

Reference is made to FIGS. 2A-C, which are schematic illustrations of alternative configurations of dental implant 30, in accordance with respective embodiments of the present invention. In the configuration shown in FIG. 2A, distal opening 41 of lumen 40 is located on distal implant end 38 at a location other than a distal tip 70 of the implant. For some applications, the location is within 3 mm of distal tip of 70, as measured along the surface of the distal tip. As mentioned above with reference to FIG. 1, for some applications, lumen 40 is open to the distal end via a plurality of distal openings 41, as shown in FIG. 2A. One or more of the openings may be at a location other than distal tip 70, including at one or more locations at distal implant end 38 and/or elsewhere on distal implant portion 48. Alternatively, lumen 40 is open to distal implant end 38 or distal implant portion 48 via exactly one opening (configuration not shown in FIG. 2A).

In the configuration shown in FIG. 2B, distal implant end 38 is concave, such that the raised edge of the concavity defines a sharp cutting surface 46. In the configuration shown in FIG. 2C, distal implant end 38 is generally flat, and the distal end is shaped so as to define sharp cutting surface 46, typically near the edge of the distal end.

Reference is made to FIG. 2D, which is a schematic illustration of yet another configuration of dental implant 30, and FIG. 2E, which is a cross-sectional view taken along line IIC-IIC of FIG. 2D, in accordance with an embodiment of the present invention. In this embodiment, lateral surface 42 of dental implant 30 is indented so as to define a channel 80 along the lateral surface between a first location 82 on the lateral surface in a vicinity of distal implant end 38, and a second location 84 on the lateral surface between distal implant end 38 and proximal implant end 34, not inclusive (i.e., the channel typically does not extend all of the way to the proximal implant end). A distal portion 88 of delivery tube 50 is positioned within the channel, such that the distal end of the delivery tube is open to distal end 38 of the implant. Alternatively, the distal end of the delivery tube is open to a location along the channel, such as a location on distal implant portion 48. For example, the distal end of the delivery tube may reach a point A in a vicinity of second location 84, such that only a small portion of the delivery tube is positioned within the channel. Typically, at least a portion of lateral surface 42 is shaped so as to define screw thread 36, at least a portion of which may or may not act as a cutting surface, and which comprises a raised helical rib going around implant 30. Channel 80 crosses the rib at a plurality of sites on the lateral surface. Typically, the second location is at least 2 mm from proximal implant end 34, such as at least 3 mm or at least 4 mm.

A number of embodiments of the present invention include positioning of lateral opening 44 (e.g., in ridge 100 and/or in regenerative material 130). The techniques of the embodiment described with reference to FIG. 2D may be performed in combination with the techniques of these embodiments by substituting second location 84 for lateral opening 44.

Reference is made to FIG. 2F, which is a schematic illustration of a removable coupling element 90 coupled to implant 30, in accordance with an embodiment of the present invention. Removable coupling element 90 removably secures delivery tube 50 to lateral opening 44. When the surgeon decouples delivery tube 50 from implant 30, as described hereinbelow with reference to FIG. 3E, the surgeon also decouples coupling element 90 from the implant. The coupling element is typically removably coupled to an external surface of the implant. For some applications, coupling element 90 is configured to be placed around at least a portion of the circumference of the implant, such as the entire circumference.

In an embodiment, coupling element 90 comprises an elastic band that is placed around the entire circumference of the implant, as shown in FIG. 2F. The distal end of delivery tube 50 may pass through an opening in the band, such that the band holds the tube in place coupled to lateral opening 44. For other applications, coupling element 90 comprises a more rigid material.

Reference is made to FIGS. 3A-F, which are schematic illustrations of several steps of a minimally-invasive closed sinus lift surgical procedure for implanting dental implant 30, in accordance with an embodiment of the present invention. The procedure is typically employed when a patient's maxillary alveolar ridge lacks sufficient bone mass to support a conventional dental implant. A surgeon begins the procedure by preparing the oral facial region, and administering a local anesthetic. Optionally, as shown in FIG. 3A, the surgeon initiates an osteotomy in a maxillary alveolar ridge 100 by making a preliminary portion of a bore using a dental drill, such as a conventional sinus bur 102. This preliminary bore portion typically has a diameter of between about 1 and about 7 mm, e.g., between about 2 and about 6 mm, and leaves residual bone thickness of between about 0.5 and about 5 mm, e.g., between about 1 and about 4 mm. The bore is measured using techniques known in the art, such as CT, x-ray, or x-ray with a depth guide.

After drilling the preliminary bore portion, the surgeon typically simultaneously forms a larger bore through maxillary alveolar ridge 100 and advances dental implant 30 into the bore by screwing the implant into ridge 100 using a surgical screwing tool 110, as shown in FIG. 3B. Screwing tool 110 may comprises a conventional manual ratchet wrench, or a conventional drill or motor to which an appropriate drill head is attached, and which is operated at a low speed and at low torque. Alternatively, screwing tool 110 may comprise a conventional hexagonal tool with a knurled knob, such as a knurled hex screwdriver, and along its axis, a thin rod having a hexagonal head which fits into a female hexagonal socket defined by a proximal end of applicator 32.

While the surgeon screws the implant, fluid source 54 provides a fluid under monitored pressure to distal implant portion 48, such as distal implant end 38, via supply tube 52, delivery tube 50, and lumen 40. The fluid typically comprises a biocompatible solution such as normal saline solution, or a gas, e.g., air. Implant 30 functions as a cork that isolates the distal end of the bore from the oral cavity, allowing relatively high pressure to develop in the fluid distal to the implant, without being released to the oral cavity. A drop in the pressure is detected as distal implant end 38 forms an opening through the top of ridge 100 to below a Schneiderian membrane 122, thereby bringing distal opening(s) 41 into fluid communication with a surface of the membrane facing ridge 100, as shown in FIG. 3B. Upon detection of the drop, the surgeon ceases screwing implant 30 to avoid perforating the membrane. Distal implant end 38 typically does not pass through the top of ridge 100, at least at this stage in the procedure.

The drop in pressure may be detected using a separate pressure gauge 124, for example for applications in which fluid source 54 comprises a manual syringe 126, as shown in FIG. 3B. Such a gauge may be coupled to supply tube 52, as shown in the figure, or directly to the syringe (configuration not shown), as is known in the art, e.g., the Viceroy™ Inflation Syringe (Merit Medical Systems, Inc., South Jordan, Utah). Alternatively, for applications in which fluid source 54 comprises a powered drug delivery device, the drop in pressure may be detected using a pressure gauge integrated into the drug delivery device, as is known in the art (configuration not shown). System 20 comprises an output unit that generates an output notifying the surgeon of the drop in pressure. The output may include an audio or visual signal. Alternatively or additionally, system 20 may display an indication of a numerical value of the measured pressure.

As shown in FIG. 3C, the surgeon gently lifts and separates membrane 122 from the top of ridge 100 into a maxillary sinus 128, by injecting a fluid 129, such as a biocompatible solution such as normal saline solution or a gas, from fluid source 54 under controlled pressure via supply tube 52, delivery tube 50, and lumen 40, so as to form a cavity 120 under the membrane between the ridge and the membrane (in FIG. 3C, the membrane is shown partially raised). System 20 generates an output indicative of a numerical value of the measured pressure, and/or a warning output if the measured pressure crosses a threshold value. An increase in the pressure generally indicates that the membrane is expanding and may perforate. Typically, the surgeon injects sufficient fluid 129 into cavity 120 to inflate the cavity to a vertical height of between about 2 and about 20 mm from the top of ridge 100, such as between about 2 and about 11 mm, e.g., between about 2 and about 8 mm. For some applications, a measured volume of fluid 129 is injected in order to achieve the desired cavity height, such as between about 0.5 and about 6 ml of fluid, e.g., between about 1 and about 4 ml.

The liquid is typically drained from the cavity, and the surgeon injects a regenerative material 130, such as liquid or gel bone graft, into cavity 120, as shown in FIG. 3D. Fluid source 54 or a separate syringe or powered drug delivery device is used for injecting the regenerative material. If a separate syringe or device is used to inject the material, the material may be provided via supply tube 52, or via a separate supply tube coupled to proximal joint portion 60 of swivel joint 64, or coupled to supply tube 52 near the applicator. Alternatively, the material may be directly injected into lumen 40 by directly coupling the syringe to the implant. Regenerative material 130 may comprise an allograph, an autogenous bone graft, or a xenograft, and may, for example, comprise a natural material, a synthetic material, or a mixture thereof. For example, regenerative material 130 may comprise one of the following commercially available liquid bone graft materials: Allomatrix (Wright), Cerament (Bone Support), DynaGraft (Citagenix/ISOTIS), Fisiograft (Ghimas), Grafton (Osteotech), Optium DBM Gel (Lifenet/Depuy J&J), OsteoMax (Orthfix), PD VitalOs Cemen (VitalOs), or Regenafil® (Exactech). Alternatively, regenerative material 130 may comprise the composition described hereinbelow that comprises saline solution mixed with solid bone graft particles. Optionally, the system monitors and generates an output indicative of the pressure of the regenerative material as it is injected.

For some applications, system 20 measures the volume of fluid 129 injected into the cavity between the ridge and the membrane while forming cavity 120, at the step of the procedure described hereinabove with reference to FIG. 3C. Responsively to the measured volume, the surgeon determines an amount of regenerative material 130 to inject into cavity 120 at the step of the procedure described hereinabove with reference to FIG. 3D. Typically, the amount of regenerative material 130 is approximately equal to the volume of injected fluid 129, or slightly greater or less than the volume of the injected fluid. As a result, waste of regenerative material 130 is generally minimized, and the likelihood of perforating the membrane by injection of the regenerative material is generally reduced.

For some applications, the surgeon uses a flexible wire as a piston to help push the regenerative material through the supply tubes and/or lumen. This technique may be helpful when the regenerative material is viscous and thus difficult to inject using an ordinary syringe.

Alternatively, the surgeon injects regenerative material 130, rather than fluid 129, to lift membrane 122, thereby combining the steps of the procedure described hereinabove with reference to FIGS. 3C and 3D. In this case, the regenerative material typically comprises a liquid.

The surgeon decouples delivery tube 50 from implant 30, and further advances (e.g., by rotating or screwing) implant 30 into regenerative material 130 in cavity 120, as shown in FIG. 3E. The surgeon may decouple the delivery tube before or while further advancing the implant, and/or by advancing the implant until the tube becomes decoupled because of the rotation. This additional advancing of the implant advances lateral surface 42 of implant 30 at least until lateral opening 44 is positioned entirely within the bore in ridge 100 and/or in regenerative material 130 in cavity 120. Such positioning of both ends of lumen 400 within bone substantially reduces the risk of infection, because proximal end 34 of implant 30 that is exposed to the oral cavity or gingiva is permanently closed. The surgeon decouples applicator 32 from implant 30, such as by pulling the male coupling element out of the female coupling element.

As shown in FIG. 3F, after bone grows into regenerative material 130 and is integrated into ridge 100, an appliance 140, such as a crown, is coupled to implant 30, typically using an abutment 142 coupled to implant 30, as is known in the art. Alternatively, as mentioned above, implant 30 comprises a single-stage transgingival implant/abutment, as is known in the art.

Reference is made to FIGS. 4A and 4B, which are schematic illustrations of respective configurations of dental implant 30 in which the implant comprises a valve 200, in accordance with respective embodiments of the present invention. In the configuration shown in FIG. 4A, valve 200 comprises a trap door valve positioned in a fluid path defined by lumen 40 near lateral opening 44. In the configuration shown in FIG. 4B, valve 200 is arranged in a fluid path defined by lumen 40. Alternatively, the valve may be arranged in delivery tube 50 (configuration not shown).

For some applications, valve 200 comprises a unidirectional valve that is configured to allow passage of material through lumen 40 or delivery tube 50 toward distal implant end 38, and to prevent the passage in an opposite direction. For these applications, valve 200 may be positioned at (a) any convenient location along lumen 40, as shown in FIG. 4A, such as in a vicinity of lateral opening 44, in a vicinity of a distal opening of the lumen, or at an intermediary location in the lumen, or (b) any convenient location along delivery tube 50 (configuration not shown).

For other applications, valve 200 is configured to allow bidirectional flow through lumen 40. For these applications, the valve may be positioned in a vicinity of lateral opening 44, and may comprise, for example, a trap door valve, a faucet valve, a duckbill check valve (e.g., comprising a biodegradable material), or a magnetic valve. The valve may comprise metal or silicone, or another biocompatible material. For some applications, the valve is configured to be opened by delivery tube 50 when the tube is coupled to implant 30, and to assume a closed position when the delivery tube is not coupled to the implant. The valve is opened during injection and drainage of fluid 129 (e.g., a biocompatible solution such as normal saline solution), as described hereinabove with reference to FIGS. 3C and 3D. For example, if the valve comprises a trap door, the trap door may be forced open by delivery tube 50. Regenerative material 130 is injected while the valve remains open, as described hereinabove with reference to FIG. 3D, and thereafter the valve is closed. For applications in which the valve comprises a trap door, the trap door may be closed by removing delivery tube 50.

For some applications, valve 200 serves to prevent regenerative material 130 from exiting cavity 120 once the material has been injected into the cavity, as described hereinabove with reference to FIG. 3D. For some applications, the sinus lift is performed by injecting fluid 129 (e.g., a biocompatible solution such as normal saline solution) using a separate dental sleeve. After cavity 120 has been formed between ridge 100 and membrane 122, the sleeve is removed, implant 130 is inserted, and regenerative material 130 is injected into the cavity via the implant.

For some applications, valve 200 is configured to be opened and closed using an open/close control accessible from outside of the implant. For example, the open/close control may comprise a thin rod that passes through the lateral surface of the implant. One end of the rod is accessible from the lateral surface, and is shaped so as to define a male or female coupling element, e.g., a hexagonal socket or a screw slot. The other end of the rod comprises an opening/closing element positioned within lumen 40. The opening/closing element is configured to block passage through the lumen when the rod is rotated in a first set of one or more rotational positions, and to allow passage through the lumen when the rod is rotated in a second set of one or more rotational positions.

Reference is made to FIG. 5, which is a schematic illustration of a dental drill 300, in accordance with an embodiment of the present invention. Drill 300 comprises a bit 310 which is shaped so as to define a lumen 340 therethrough that is open to a distal portion of the bit that extends from a distal end 314 of the bit along up to 8 mm of a longitudinal length of the bit, such as up to 6 mm of the length, up to 4 mm of the length, or up to 2 mm of the length. For some applications, lumen 340 is open to distal end 314 of the bit, either at the tip of the bit or in the general area of the distal end of the bit. The surgeon uses drill 300 to perform a controlled sinus lift procedure. Drill 300 is coupled to a source of pressure 354. While the surgeon drills a bore through the maxillary alveolar ridge, fluid source 54 provides a fluid under monitored pressure to the distal bit portion, such as distal bit end 314, via lumen 340. The fluid typically comprises a biocompatible solution such as normal saline solution, or a gas, e.g., air.

Bit 310 functions as a cork that isolates the distal end of the bore from the oral cavity, allowing the development of relatively high pressure in the fluid, as described hereinabove. Alternatively, an o-ring is provided around the bit to provide a seal. A drop in the pressure is detected as distal bit end 314 forms an opening through the top of ridge 100 to below a Schneiderian membrane (similar to the step of the earlier described procedure shown in FIG. 3B), thereby bringing the distal opening into fluid communication with a surface of the membrane facing the ridge. Upon detection of the pressure drop, the surgeon ceases drilling to avoid perforating the membrane. For some applications, the drill automatically ceases drilling upon detecting the drop in pressure, while for other applications, the drill generates an output notifying the surgeon of the drop in pressure. The output may include an audio or visual signal. Alternatively or additionally, the drill may display an indication of a numerical value of the measured pressure.

After penetrating the ridge, the surgeon performs a sinus lift, either using techniques described herein (such as injecting a fluid under controlled pressure), or using techniques known in the art. For some applications, the surgeon inserts dental implant 30 into the bore, which is not necessarily provided with swivel joint 64. For other applications, the surgeon inserts a conventional dental implant into the bore.

Reference is made to FIGS. 6A-C, which are schematic illustrations of configurations of a dental implant system 420, in accordance with respective embodiments of the present invention. System 420 comprises a dental implant 430, which is shaped so as to define a lumen 440 therethrough having at least one distal opening 441 through a distal external surface of a distal portion 448 of the implant that extends from a distal implant end 438 of the implant along up to 50% of a longitudinal length of the implant, such as up to 30% of the length, up to 15% of the length, or up to 5% of the length. For some applications, distal portion 448 has a longitudinal length of up to 8 mm, such as up to 6 mm, up to 4 mm, or up to 2 mm. Distal opening 441 may be located at distal implant end 438, such as centered on the distal implant end, e.g., at a distal tip of distal implant end 438, or not centered on the distal implant end (and thus located at a location other than the distal tip), such as described hereinabove with reference to FIG. 2A. Alternatively, distal opening(s) 441 may be located at one or more locations along distal implant portion 448, including at locations on a lateral surface of the implant.

System 420 further comprises an applicator 460 that is removably coupled to a proximal end 434 of implant 430 during a portion of an implantation procedure. The applicator comprises a chamber 466 that is in fluid communication with lumen 440, and an elastic pressure-applying element 468 that is configured to apply pressure to the chamber. While the surgeon screws the implant into the alveolar ridge, pressure is applied by fluid in chamber 466 to distal implant end 438 via lumen 440. A drop in the pressure is detected as the distal implant end forms an opening through the top of the ridge to below a Schneiderian membrane, thereby bringing the distal opening into fluid communication with a surface of the membrane facing the ridge. Upon detection of the pressure drop, the surgeon ceases to screw the implant. Although the entire applicator, including the entire pressure-applying element, is shown in FIGS. 6A-C as being sized to be positioned within an oral cavity of the subject, for some applications a portion of the applicator, such as a portion of the pressure-applying element, is configured to be positioned outside of the oral cavity. For example, all or part of the pressure-applying element may be in fluid communication with the applicator via one or more tubes (configuration not shown).

In the configuration shown in FIG. 6A, elastic pressure-applying element 468 comprises a balloon 470 shaped so as to define chamber 466. For some applications, the pressure is applied by initially inflating balloon 470 with fluid to greater than atmospheric pressure. Alternatively or additionally, the pressure is applied by the surgeon squeezing the balloon in conjunction with screwing the implant.

In the configurations shown in FIGS. 6B and 6C, applicator 460 comprises a piston 480 and a spring 482 configured to apply pressure to chamber 466. In the configuration shown in FIG. 6B, the spring, piston, and chamber are arranged such that the spring applies pressure in a proximal direction on the piston, and the chamber is positioned proximal to the piston. In this configuration, the chamber is typically in fluid communication with lumen 440 via a delivery tube 450, a distal end of which is removably coupled to lumen 440 via a lateral opening 444 in an external lateral surface 442 of implant 430, and a proximal end of which is coupled to the chamber.

In the configuration shown in FIG. 6C, the spring, piston, and chamber are arranged such that the spring applies pressure in a distal direction on the piston, and the chamber is positioned distal to the piston. In this communication, a proximal end of lumen 440 is typically open to the chamber at proximal end 434 of the implant via a proximal opening, and the chamber is in fluid communication with lumen 440 via the proximal opening.

For some applications, the chamber contains a fluid, and the applicator comprises an indicator element 484 that is arranged with the piston to indicate when the pressure applied to the chamber has caused ejection of at least a portion of the fluid from the chamber out of distal implant end 438 via lumen 440. For example, in the configuration shown in FIG. 6B, movement of piston 480 in a proximal direction causes indicator element 484 to protrude from a proximal end of applicator 460, and in the configuration shown in FIG. 6C, movement of the piston in a distal direction causes the indicator element to retract into the proximal end of the applicator.

For some applications, as illustrated in FIG. 6C (but equally applicable to the embodiments described with reference to FIGS. 6A and 6B), implant 430 comprises a plug 490 removably coupled to the implant so as to seal the distal end of lumen 440. The plug is typically biodegradable. The plug comes loose during the implantation procedure by friction generated by the screwing of the implant, allowing the fluid to escape from the chamber as the distal implant end forms an opening through the top of the ridge into the cavity. For some applications, the plug comprises regenerative material, such as bone graft.

For some applications, the techniques described with reference to FIGS. 6A-C are practiced in combination with those described hereinabove with reference to FIGS. 1, 2A-C, 3A-3F, and/or 4A-B. By way of example and not limitation, implant 430 may comprise a self-tapping implant having a cutting surface, such as a screw thread.

Reference is made to FIG. 7, which is a schematic illustration of a removable sheath 500 applied to a dental implant 530, in accordance with an embodiment of the present invention. Prior to performance of an implantation procedure, sheath 500 is placed on the implant such that the sheath covers at least a portion, e.g., substantially all, of a lateral external surface 542 of the implant, and, optionally, at least a portion of an applicator 532 coupled to the implant, and such that at least a portion of a distal end 438 of the implant is exposed. For some applications, a ring-shaped distal opening of the sheath is somewhat rigid in order to main the shape of a distal opening of the sheath. For some applications, a proximal opening of the sheath is elastic in order to tightly couple the sheath to applicator 532. Alternatively, sheath 500 is placed on the implant such that the sheath covers at least a portion (e.g., all) of a proximal end 534 of the implant. For some applications of this configuration, applicator 532 is not provided, while for other applications, the applicator is coupled to the proximal end of the implant such that the sheath is held between the proximal end of the implant and a distal end of the applicator. Upon decoupling the applicator from the implant, the sheath is no longer held in place.

During the implantation procedure, the surgeon inserts the implant into an alveolar ridge, such as a maxillary or mandibular alveolar ridge. The surgeon inhibits infection by removing the sheath from the implant in conjunction with the inserting.

For some applications, the techniques described with reference to FIG. 7 are practiced in combination with those described hereinabove with reference to FIGS. 1, 2A-C, 3A-3F, 4A-B, and/or 6A-C. By way of example and not limitation, implant 430 may comprise a self-tapping implant having a cutting surface, such as a screw thread, and/or may be shaped so as to define a lumen 540 therethrough that is open through a distal opening to a distal portion of the implant, such as distal implant end 438.

Reference is made to FIGS. 8A and 8B, which are schematic illustrations of a biodegradable dental sleeve 600 in closed and open positions, respectively, in accordance with an embodiment of the present invention. Dental sleeve 600 is configured to be inserted into a bore formed through a portion of a maxillary alveolar ridge, as described below, or through another bone, such as a mandibular alveolar ridge. The sleeve comprises a tubular portion 610 having proximal and distal ends 612 and 614, and shaped so as to define a lumen 616 therethrough. The tubular portion may be generally cylindrical, tapered, or conic in shape, and/or may have another shapes, e.g., may be hexagonal in cross-section. The sleeve further comprises a biodegradable valve 620 coupled to distal end 614 of tubular portion 610, and configured to allow flow through the lumen in a direction from proximal end 612 to distal end 614, as indicated schematically by an arrow 622 in FIG. 8B, and to prevent flow in the opposite direction by closing, as shown in FIG. 8A. Tubular portion 610 and valve 620 typically comprise a flexible material, such as collagen, polylactic acid, or polyglycolic acid. For some applications, valve 620 comprises a flexible duckbill check valve, as is known in the art.

During a surgical procedure to implant a dental implant (the implant is not shown in FIGS. 8A-B), a surgeon forms a bore in the maxillary alveolar ridge, and lifts the Schneiderian membrane to form a cavity under the membrane between the ridge and the membrane, such as using techniques described herein or known in the art. After lifting the membrane, the surgeon inserts sleeve 600 into the bore, and injects a regenerative material into the cavity (such as described hereinabove, e.g., a liquid regenerative material) through lumen 616 and valve 620. Valve 620 prevents the regenerative material from exiting the cavity. The surgeon mounts a dental implant, such as an implant described herein or known in the art, in the bore by rotating the implant until a distal portion thereof breaks through valve 620 into the cavity. At this stage of the procedure, the implant blocks exit of the regenerative material from the cavity. The surgeon leaves the valve in place in the bore to biodegrade, and be absorbed. Typically, tubular portion 610 is biodegradable, and is left in the bore along with valve 620. Alternatively, the tubular portion and the valve are configured to be readily separated from one another, and, after mounting the dental implant in the bore, the surgeon separates the tubular portion from the valve and withdraws the tubular portion from the bore.

Reference is made to FIG. 9, which is a schematic illustration of a controlled bone penetration system 700, in accordance with an embodiment of the present invention. System 700 comprises a drilling element 710, which may comprise, for example: (a) a dental drill bit, such as known in the art, or described hereinabove with reference to FIG. 5 (as shown in FIG. 9); (b) a dental implant, such as known in the art, or described hereinabove; or (c) a generally cylindrical sleeve, such as described, for example, in above-mentioned US Patent Application Publication 2006/0084034 to Hochman. System 700 further comprises a light sensor 712, which is configured to sense a level of illumination at a distal end 714 of drilling element 710, such as at a distal tip. Light sensor 712 comprises a light detecting element. For some applications, the light detecting element is positioned at distal end 714, as shown in the figure. For other applications, the light detecting element is positioned remotely from distal end 714, and is in optical communication with the distal end, such as via one or more fiber optic cables that pass through drilling element 710 (configuration not shown).

System 700 further comprises a light source 720, which is configured to be positioned so as to provide substantially more illumination in the vicinity of light sensor 712 when distal end 714 of drilling element 710 has penetrated through a bone, such as the maxillary alveolar ridge, than before the distal end penetrates the bone. For example, light source 720 may be positioned in a nasal cavity 722 of the subject or near the nasal cavity outside the body (e.g., on a cheek of the subject), such that light emitted by the light source into the nasal cavity illuminates an interior of a maxillary sinus 128 through the wall of the sinus and/or via an anatomical opening between sinus 128 and a middle nasal meatus of nasal cavity 722. Alternatively, the light source is positioned in the maxillary sinus (configuration not shown). Further alternatively, the light source is positioned in an oral cavity of the subject, and illuminates the maxillary sinus via the palate (configuration not shown).

Further alternatively, light source 720 is positioned adjacent to light sensor 712 on drilling element 710. The level of illumination sensed by light sensor 712 changes as the distal tip of the implant breaks through the bone. For some applications, the light source and/or the light sensor are positioned remotely from the distal end of drilling element 710, and are in optical communication with the distal end, such as via one or more fiber optic cables that pass through drilling element 710 (configuration not shown).

System 700 further comprises an output unit 740, which is configured to generate an output indicative of the illumination sensed by light sensor 712. For example, the output may indicate a level of the light detected, such as numerically or by a tone configured to indicate the level (e.g., by varying its pitch and/or volume), and/or to indicate when the detected level of illumination crosses a threshold level.

During an implantation procedure, the surgeon positions light source 720 at the desired location, and begins creating a bore in the maxillary alveolar ridge using drilling element 710. As distal end 714 and light sensor 712 approach the top of the ridge, the light sensor detects a rapid increase in the amount of light reaching the detector from light source 720. Typically, but not necessarily, the detected light varies as a sigma function with respect to the distance the distal implant travels. Responsively to this measurement of light intensity, the surgeon may decrease the rotational speed of the drill as the distal end approaches penetration out of the bone. When the distal end 714 forms an opening through the top of ridge 100 to below a Schneiderian membrane 122, the light sensor detects a substantial increase in illumination, and the surgeon ceases drilling.

In an embodiment of the present invention, light source 720 is configured to emit light from distal end 714 of drilling element 710, and light sensor 712 is positioned remotely from the distal end to detect the emitted light, such as in nasal cavity 722 or outside of the cavity, such as outside of a body of the subject. The light sensor, whether positioned in the cavity or not, is configured to sense a level of the emitted light within the cavity.

For some applications, system 700 is used for controlled penetration of another body structure, such as another bone, a brain, a spinal cord, a cyst, or another lesion in a bone. For example, the lesion may be in a body part in which the lesion has different optical properties from the native tissue. For some applications, the lesion is a vascular lesion, such as a vascular tumor.

For some applications, system 700 is used for controlled penetration of a tumor. Tumors often are optically distinct from surround tissue, such as because the tumors have greater blood supply than surrounding tissue, or different density than that of surrounding tissue (e.g., greater opacity than that of surrounding tissue). For some applications, light source 720 generates light at two different wavelengths, and the system analyzes the detected light at the two wavelengths to detect a level of blood supply, such as using techniques known in the pulse oximetry art. A greater level of blood indicates that the tool has penetrated into the tumor.

For some applications, system 700 is used for controlled penetration of a needle into a uterus during amniocentesis. The penetration is alternatively or additionally detected by detecting a change in pressure, using techniques described hereinabove. Similarly, system 700 and/or the pressure change detection techniques described herein may be used for detecting penetration of an epidural needle into the epidural space at the base of the spine.

In an embodiment of the present invention, the techniques described herein are used for performing nasal floor elevation, mutatis mutandis, in order to implant a dental implant in the incisor position. A bore is formed through a maxillary alveolar ridge in a region of the upper incisors from the front side, and the implant is inserted into the bore at least until the distal opening comes into fluid communication with a surface of a nasal floor membrane facing the ridge. The membrane is raised to form a cavity between the ridge and the membrane.

In an embodiment of the present invention, the techniques described herein are used with an inclined entry, for patients in which the residual bone of the maxillary alveolar ridge is too thin to achieve stability. A bore is formed with an inclined entry at a location adjacent the site of the implant where there is sufficient bone, and sinus lift is performed via the bore using the techniques described herein, mutatis mutandis, such as the techniques described hereinabove with reference to FIG. 5, or with reference to FIGS. 1, 2A-F, 3A-F, 4A-B, 6A-C, 7, and/or 8. For some applications, the bore is formed using a biodegradable drilling element that is configured to biodegrade as the regenerative material integrates with the native bone. Regenerative material is injected into the cavity between the ridge and the Schneiderian membrane. Prior to or after the material integrates, a second straight bore is made at the desired implant location through the thin preexisting bone and into the regenerative material or new bone, and a conventional implant is inserted into the bore.

In an embodiment of the present invention, the techniques described herein are used with a palatal entry. A bore is formed in the palate (which is thicker than the maxillary alveolar ridge), and sinus lift is performed via the bore using the techniques described herein, mutatis mutandis, such as the techniques described hereinabove with reference to FIG. 5, or with reference to FIGS. 1, 2A-F, 3A-F, 4A-B, 6A-C, 7, and/or 8. For some applications, the bore is formed using a biodegradable drilling element that is configured to biodegrade as the regenerative material integrates with the native bone. The drilling element is withdrawn or allowed to biodegrade. Regenerative material is injected into the cavity between the ridge and the Schneiderian membrane. Prior to or after the material integrates, a second bore is made at the desired implant location through the maxillary alveolar ridge and the new bone, and a conventional implant is inserted into the bore.

In an embodiment of the present invention, the regenerative material comprises a composition comprising solid bone graft particles mixed with a physiological solution, such as saline solution, blood, or diluted blood. For example, the solid bone graft particles may comprise freeze-dried bone allograft (FDBA). Typically, the volume concentration of the particles in the composition before filtering is less than 50%, e.g., less than 25%, such as between about 10% and about 20%, as described below. For some applications, two bores are formed through the maxillary alveolar ridge to below the Schneiderian membrane. The regenerative material is injected though a first bore, and at least a portion of the physiological solution drains through a filter in (or in communication with) the second bore, leaving at least a portion of solid bone graft particles in a cavity formed between the ridge and the membrane. Typically, the volume concentration of the particles in the composition after filtering is greater than 50%, e.g., between about 80% and about 100%. For some applications, this technique is used for bones other than the maxillary alveolar ridge, such as a mandibular alveolar ridge.

It will be appreciated by persons skilled in the art that the present invention is not limited to what has been particularly shown and described hereinabove. Rather, the scope of the present invention includes both combinations and subcombinations of the various features described hereinabove, as well as variations and modifications thereof that are not in the prior art, which would occur to persons skilled in the art upon reading the foregoing description. 

1. Apparatus comprising: a dental implant having a proximal-most part, a lateral external surface, and a distal implant portion that extends from a distal implant end along up to 50% of a longitudinal length of the implant, the implant being shaped so as to define a lumen therethrough (a) having at least one distal opening through a distal external surface of the distal implant portion, (b) having a lateral opening through the lateral external surface, and (c) not open to a proximal external surface of the implant within 2 mm of the proximal-most part of the implant; and a delivery tube having a proximal tube end and a distal tube end, which distal tube end is removably coupled to the implant such that the delivery tube is in fluid communication with the lumen via the lateral opening when the delivery tube is coupled to the implant. 2-3. (canceled)
 4. The apparatus according to claim 1, wherein the dental implant is permanently closed within 3 mm of the proximal-most part of the implant. 5-7. (canceled)
 8. The apparatus according to claim 1, wherein the lateral opening is at least 3 mm from a proximal implant end.
 9. The apparatus according to claim 1, wherein at least a portion of the lateral external surface is shaped so as to define a cutting surface.
 10. The apparatus according to claim 9, wherein the lateral opening is within the portion of the lateral external surface that defines the cutting surface. 11-17. (canceled)
 18. The apparatus according to claim 1, further comprising an applicator, which is removably coupled to a proximal implant end of the implant. 19-128. (canceled)
 129. The apparatus according to claim 1, wherein the implant is shaped so as to define exactly one lateral opening to the lumen through the lateral external surface.
 130. The apparatus according to claim 1, wherein the implant is shaped so as to define exactly one lumen therethrough.
 131. The apparatus according to claim 1, wherein the proximal-most part of the implant is shaped so as to define an abutment-coupling surface.
 132. The apparatus according to claim 131, further comprising an abutment, which is configured to be coupled to the abutment-coupling surface.
 133. The apparatus according to claim 1, wherein the implant is shaped so as to define an integrated abutment.
 134. The apparatus according to claim 1, wherein the portion of the lateral external surface that includes the lateral opening has a circular cross-section perpendicular to a central longitudinal axis of the implant.
 135. The apparatus according to claim 1, wherein the implant is shaped such that rotation of the implant advances the implant through a bore in a bone ridge so that the lateral opening advances entirely into the bore.
 136. Apparatus comprising a dental implant having a proximal-most part, a lateral external surface, and a distal implant portion that extends from a distal implant end along up to 50% of a longitudinal length of the implant, the implant being shaped so as to define: a lumen therethrough (a) having at least one distal opening through a distal external surface of the distal implant portion, and (b) not open to a proximal external surface of the implant within 2 mm of the proximal-most part of the implant, and exactly one lateral opening to the lumen through the lateral external surface of the implant.
 137. The apparatus according to claim 136, wherein the implant is shaped so as to define exactly one lumen therethrough.
 138. The apparatus according to claim 136, wherein the proximal-most part of the implant is shaped so as to define an abutment-coupling surface.
 139. The apparatus according to claim 138, further comprising an abutment, which is configured to be coupled to the abutment-coupling surface.
 140. The apparatus according to claim 136, wherein the implant is shaped so as to define an integrated abutment.
 141. The apparatus according to claim 136, wherein the portion of the lateral external surface that includes the lateral opening has a circular cross-section perpendicular to a central longitudinal axis of the implant.
 142. The apparatus according to claim 136, wherein the implant is shaped such that rotation of the implant advances the implant through a bore in a bone ridge so that the lateral opening advances entirely into the bore.
 143. The apparatus according to claim 136, further comprising an applicator, which is removably coupled to a proximal implant end of the implant.
 144. The apparatus according to claim 136, wherein the dental implant is permanently closed within 3 mm of the proximal-most part of the implant.
 145. The apparatus according to claim 136, wherein the lateral opening is at least 3 mm from a proximal implant end of the implant. 